Those that break treaties should be punished soundly. To avoid "no-one will sign treaties because they plan to break them, eventually" treaties can be made to have a strict duration (1 day, 1 week, 1...

Pernament terrain change (like blasting hills, etc.) is not that good in a war-intensive game (as we will end up in a giant hole sooner and later that way). And if it is possible to burn the forests,...

An undead "race" could exist. Or an organised "group", rather. Whereas humans, elves or orcs are united by traditions and common goals, The Undead are united by common agenda only (such as hatred of...